PRACTICAL ORGANIC a Jreflux It It consists of a boiling-tube, through the bottom"1 stout platinum wire is sealed, which is intended external liquid an< bles at Above layer, - deep, of The obj beads is t° the bubbles vent superl irregular the side condenser to cornier* «e l^ va. pours given oil clUrjng the boiling- A Beck- mann thcrnlometer is inserted tliroug^ the mouth of the tube. This thermometer is similar in <^onst*~Uction to that used for freez. ing-point c|ete*"inma- tions, but it l^as a smaller Ui-ilb. The boiling--tul:>*^ is placed in the central cavity of a hollow gla.ss or porcelain jtxcket, \vhich contains the same liquid as tlie "boiling- tube and is also pro- vided with. £t condenser. This jaclcot prevents radiation, fromtVie boil- ing-tube. It Is pro- vided with two windows of mica. The jacket is c:li.xrnpecl on a gauze ring supported on a square tray of asbestos plitced upon a FIG. 32.